Tie down clamp



FIG. 1 is a front and right side perspective view of a tie down clamp showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side elevational view thereof; and

FIGS. 4 and 5 are respectively top and bottom plan views thereof. 

The ornamental design for a tie down clamp, as shown and described. 